Electrical Engineering Calculators — Engineering

Estimate battery runtime from capacity (mAh/Wh) and device power consumption.

Determine cable ampacity (current-carrying capacity) based on NEC tables and derating factors.

Calculate cable tray width from cable count, diameters, and NEC fill requirements.

Size capacitor banks for power factor correction from measured kW, kVA, and target PF.

Calculate conduit fill percentage based on NEC code for wire types and conduit size.

Calculate total electrical panel load from all branch circuits for service sizing.

Calculate emergency lighting unit count from floor area and lux requirements.

Calculate electrical energy cost from power consumption, usage hours, and utility rate.

Calculate the correct fuse or circuit breaker size from load current and wire gauge.

Calculate earth grounding resistance from rod dimensions and soil resistivity.

Calculate energy stored in an inductor from inductance and current.

Calculate the inverter size needed for off-grid or backup power from total load wattage.

Calculate the number and spacing of light fixtures needed for target lux levels.

Convert between lux (illuminance) and lumens (luminous flux) based on area.

Calculate electric motor horsepower from voltage, current, efficiency, and power factor.

Calculate inrush current at motor startup from nameplate FLA and code letter.

Interactive Ohm law wheel calculator showing relationships between voltage, current, resistance, and power.

Calculate minimum PCB trace width for a given current using IPC-2221 standards.

Calculate the capacitor bank size needed to improve power factor to a target value.

Calculate RC circuit time constant and charging/discharging curves.

Calculate resonant frequency, impedance, and Q factor for series and parallel RLC circuits.

Size a solar panel system from daily energy usage, sun hours, and panel wattage.

Calculate solenoid pull force from coil turns, current, area, and plunger position.

Convert between star (Y) and delta (triangle) resistor configurations.

Calculate stepper motor holding and pull-out torque from specs and operating conditions.

Calculate transformer turns ratio, voltage, and current from primary and secondary specifications.

Calculate UPS backup runtime from battery capacity, load, and efficiency.

Calculate unknown resistance in a Wheatstone bridge from three known resistances.